The present invention relates generally to an apparatus for grinding an out-of-round trunnion or tire for a rotary kiln and, more particularly, to a self-adjusting assembly for grinding an out-of-round trunnion or tire into round.
Tubular rotary kilns are commonly used in the manufacture of cement and pulverized lime and in drying other solid and granular materials. The kilns are supported and rotate on trunnion roller mountings that cooperate with a tire surrounding the shell of the kiln.
Wear on the trunnion rollers is an inevitable consequence of the friction that occurs between the kiln tire and the trunnion rollers. At some point, either the kiln tire or the trunnion rollers will become out-of-round (usually concave). There are several negative consequences to an out-of-round kiln tire or trunnion roller. First, as the wear continues, the contact surface on the kiln tire and the trunnion roller decreases, and the kiln becomes difficult to control. Second, since the trunnion roller turns approximately three times for every revolution of the kiln tire, the surface of the trunnion roller will become harder than the surface of the tire as a result of work hardening. When the hardness relationship between the kiln tire and the trunnion roller is out of balance, spalling occurs on the surface of the kiln tire. Third, if the surfaces of the kiln tire and the trunnion rollers wear to the point that the kiln is not free to move uphill or downhill on the surface of the trunnion roller, the kiln will move in the direction of the kiln thrust. Thus, the shaft of the trunnion roller is forced against a thrust collar or thrust plate and high-heating temperatures will result. Fourth, wear on the surface of the tire or trunnion roller ultimately reduces the operating efficiency of the kiln, and, thus, unnecessarily increases the consumption of energy.
A need exists for a machine to be used on-site to address both the wear of kiln tires and trunnion rollers to place them back in round.